1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 35 #include <limits.h> 36 #include <ctype.h> 37 #include <errno.h> 38 #include <stdlib.h> 39 40 41 /* 42 * Convert a string to a long integer. 43 * 44 * Assumes that the upper and lower case 45 * alphabets and digits are each contiguous. 46 */ 47 48 long 49 strtol(const char * __restrict nptr, char ** __restrict endptr, int base) 50 { 51 const char *s; 52 unsigned long acc; 53 char c; 54 unsigned long cutoff; 55 int neg, any, cutlim; 56 57 /* 58 * Skip white space and pick up leading +/- sign if any. 59 * If base is 0, allow 0x for hex and 0 for octal, else 60 * assume decimal; if base is already 16, allow 0x. 61 */ 62 s = nptr; 63 do { 64 c = *s++; 65 } while (isspace((unsigned char)c)); 66 if (c == '-') { 67 neg = 1; 68 c = *s++; 69 } else { 70 neg = 0; 71 if (c == '+') 72 c = *s++; 73 } 74 if ((base == 0 || base == 16) && 75 c == '0' && (*s == 'x' || *s == 'X')) { 76 c = s[1]; 77 s += 2; 78 base = 16; 79 } 80 if (base == 0) 81 base = c == '0' ? 8 : 10; 82 acc = any = 0; 83 if (base < 2 || base > 36) 84 goto noconv; 85 86 /* 87 * Compute the cutoff value between legal numbers and illegal 88 * numbers. That is the largest legal value, divided by the 89 * base. An input number that is greater than this value, if 90 * followed by a legal input character, is too big. One that 91 * is equal to this value may be valid or not; the limit 92 * between valid and invalid numbers is then based on the last 93 * digit. For instance, if the range for longs is 94 * [-2147483648..2147483647] and the input base is 10, 95 * cutoff will be set to 214748364 and cutlim to either 96 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 97 * a value > 214748364, or equal but the next digit is > 7 (or 8), 98 * the number is too big, and we will return a range error. 99 * 100 * Set 'any' if any `digits' consumed; make it negative to indicate 101 * overflow. 102 */ 103 cutoff = neg ? (unsigned long)-(LONG_MIN + LONG_MAX) + LONG_MAX 104 : LONG_MAX; 105 cutlim = cutoff % base; 106 cutoff /= base; 107 for ( ; ; c = *s++) { 108 if (c >= '0' && c <= '9') 109 c -= '0'; 110 else if (c >= 'A' && c <= 'Z') 111 c -= 'A' - 10; 112 else if (c >= 'a' && c <= 'z') 113 c -= 'a' - 10; 114 else 115 break; 116 if (c >= base) 117 break; 118 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 119 any = -1; 120 else { 121 any = 1; 122 acc *= base; 123 acc += c; 124 } 125 } 126 if (any < 0) { 127 acc = neg ? LONG_MIN : LONG_MAX; 128 errno = ERANGE; 129 } else if (!any) { 130 noconv: 131 errno = EINVAL; 132 } else if (neg) 133 acc = -acc; 134 if (endptr != NULL) 135 *endptr = (char *)(any ? s - 1 : nptr); 136 return (acc); 137 } 138 139 140 long __strtol_internal(const char *number, char **_end, int base, int group); 141 142 long 143 __strtol_internal(const char *number, char **_end, int base, int group) 144 { 145 // ToDo: group is currently not supported! 146 (void)group; 147 148 return strtol(number, _end, base); 149 } 150 151